Service-meter system.



W. REID.

SERVICE METER SYSTEM.

APPLICATION FILED DEG. 5, 1907.

929,708. Patented Aug. 3, 1909.

' awe? eq UNITED STATES PATEN T OFFICE.

WILLIAM REID, ()l" CHICAGO, ILLINOIS, ABSIGNUR. 'lt) KlGLLOGG SWITUIIIIUARI) AND SUPPLY ('UMIANY, (ll CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

SERVICE-METER SYSTEM.

Specification of Letters Patent.

Patented Aug. 3, 1909.

Application filed December 5. 1907. Serial No. 406,141.

V ments in Service-h'lcter Systems, of which the l'ollmring is a specification.

My invention relates to service meter systems for telephone lines, and especially to svstems ol' the central enerry ty 0 having t tree conductor multi )l(- iac lis at t to central ollice. In systems ol tlus character it. has been the practice to place a service meter lor the linc in series or in multiple ith the coil of the cut-off relay and to actuate the service meter by impressing upon the circuit a voltage greater than that necessary for the actuation of the cut-off 'rclay. When this is done it has been found that a reversal of the current throu li the supervisory apparatus connected with the cord circuitoccurs which causes a demagnetization and romagnetization of the sleeve supervisory relay ol the cord circuit which sometimes has suilicient reactive effect to throw the service meter from its arV-tuated position back to its normal position, \rhereb i a second call could he registoredngainst t to subscriber.

The object of my present invention is to overcome the effect of such reactive current and to prevent the sleeve supervisory relay ol the cord circuit. from having its magnetism reversed by the reversal of the current actuated, whereby the full effect of the cur-.

rent in the coil will he accessible for holding the meter in its actuated posilion.

Other objects of my u'wcution will he brought out in the l'ollou'inti ilcsciipt-ion and claims. 7

My invention is illustrated in the accompanving drawing in which all apparatus is shown in'its normal and unactuated condition and is uni'lelfstood to be shown only in conventional form and to ht. typical of any apparatus nhich may lit adapted to the same USE.

The calling subscrihers station I has the condenser 2 and annunciator 3 ermancntly connected between the line cont uctors 4 and 5, and the transmitter 6 and receiver 7 in a circuit maintained normally open by contacts of the switch hook R. tor 4 connects with the live wk of battery A at the central ollice through contacts 9 and 10 of cut-oil relay 1 1 and the coil of line rela l2; and the line conductor 5 connects fit the ground ole of battery A through contacts 13 one 14 of cut-olf relay 11. Line relay 12 controls the normally open contacts 15 and 16 in the circuit. of the line lamp 17. Service meter 18 has the actuating coil 19 and the differential coil 20 normally connected in series, one terminal of coil 20 heing con nected with earth, and the other terminal of coil 30 being adapted to be connected with earth by contacts .21 and 22 when the meter is actuated. connected through the coil of cut-ofl' relay 11 and conductor 23 with the sleeve contacts 24 of the answering and multiple jacks. The tip and ring contacts 25 and 26 oi these jacks are. connected to the inside contacts 27 and 28 of the cut-oil relay 11.

The called line and substation are similarl v equipped with apparatus of the same general character, the correspondingapparatus of this line being figures with the suflix The cord circuit for connecting these lines for conversation has the tip and ring talking strands. The tip strand extends from the tip St) of the answering plug through conductor 1-H, condenser 32 and conductors 33 and 3-4 to the'tip contact 35 of the callingplug, while the ring strand c\t'ends from the ring contact 36 of the answering plug through conductor 37, condenser 38 and conductor b9 to the ring! contact it) of the calling plug. In addition to the talking strands, each connecting cord has a sleeve strand, the sleeve 41 of the answering plus being connected through conductor 42 and the coil 43 of slctvcrelay -'l-lwith the live pole of battery A and the sleeve contact 45 ol'thc callin c plug being: connected through conductor 46 and the coil of role) 4-7 with the live pole of ha-ttcry A.

The cord circuit is pro\-'ided with a pair of supervisory relays 4S and -19, relay -18 having a coil connected between tip conductor 31 The line conduc- 30 The other terminal of coil 19 is 75 designated It like 85 and the ground pole of hnttcry A, and n ecohd coil connected lictwcen the sleeve conductor 37 and contact 541 oi relay 41, this contact being adapted to he connected through contact 51 with the live pole of battery A when the relay 14 is actuated. The contact 50 of relay 11 also connects through the normally closed contacts 52 and 53 of relay 48 with the supervisory signal 54, the other terminal of that signal being con nected with the ground ole of battery A. Relay 49 also has two coils, one eoil being connected between tip conductor 33 and the ground pole of battery A, and. the other being connected between the sleeve conductor 2;?) and the contact 55 of relay 7, contact 55 being adapted to connect through the con tact 56 with the live ole of battery A when relay 47 is actuated? (ontact 55 is also normally connected through closed contacts 57 and 58 with the su Jervisory si 'nal 59, the other terminal of t at signal heing connected with the ground pole of battery A. Role 49 also has the normally open contact 60 a apted to connect with contact 57 when the relay is actuated, this contact 60 connecting through the conductor 61 with the coil of relay 62, the conductor 61 being also connected with the contact 63 of relay 62, which is adapted to connect tl'irough the contact 64 of relay 62, and conductor 65 with the contact 55 of relay 47. Relay 62 also has the normally open contacts 66 and 67, con tact 67 being connected with the contact 68 of the service meter key 69, this key having the normally open contact 7U connecting through the coil of the position meter 71 with one pole of the direct current generator 72. The other contact 66 of relay 62 connects throu h conductor 73 and the coil 7 4 of relay 44 wit the sleeve conductor 42 of the cord circuit.

Supervisory relay 47 has the normally open contacts.75 and 76 normally maintaining the se aration lietw'een the portions 33 and 34 of t is tip talking strand. Contact 76 is normally connected through contact 77 and conductor 78 with lhe auxiliary contact 79 of the o erators listening key 86, contact 79 being adapted to connect with the ll]1})0- dance coil 81 and the condenser 82 through contact 83 when the listening key is actuated. The other terminal of condenser 82 is connected throiwh the tertiary winding of the operators inuiction coil and conductor 84 with the live pole of batter A. The secondary of the operator's lllt uction coil, the

operators receiver 85 and the condenser 86 are ada ted to be placed in a bridge between the tal ing conductors hy the actuation of the listening key 80.

The calling end of the cord circuit is provided with the operators ringing key 87 hav ing normally closed series contacts in both the tip and ring conductors of the cord cirwit, the tip spring of the key hcing adapted \Vl'lflflfll'itllfttfll to connect with the contact 548, and thence through the ringing current generator 8!] to earth, and the sleeve spring of the ringing key being adapted to connect 'llirough the contact 96 with earth.

in the operation of the systcn'i thus doscrilzed the calling sulscrilier at sul station 1 removes his receiver 7 from the switch hook 8 and completes n circuit from the live pole ol lnttcry A through the coil of the linc relay 12, contacts 10 and 9 of cut-oil relay 11, line conductor 4-, transmitter 6, receiver 7, switch hook is, line conductor 5 and contacts 13 and 14 of cut-oil relay 11 toground. (urrent in this path actuates line relay 12 closing its contacts 15 and 16 in the circuit of the line lamp 17. This displays the line signal and indicates to the operator that a connection is desired hy the sul'scriher connected 35 with the jack so designated.

Upon olhserving the signal the operator inserts her answering plug into the ack of the calling line and causes the tip, ring and sleeve contacts 30, 36 and 41 of the answering plug to register with the tip, ring and sleeve contacts 25, 26 and 24 of the line jack. The circuit is therefore completed from the live pole of lnttery A through the coil 43 of supervisory relay 44, conductor 42, sleeve contacts 41 and 24 of the plug and jack, conductor 23, the coil of the cut-oil relay 11 and windings 19 and 20,in-,serics, of the line service meter to ground. The current in this path is sullicient to actuate hoth relays 44 and 11' hut is not suilicient to actuate the line service meter, partially on account of its non-inductive turns 20, and artially on account of the fact that the l I-httery voltage is not sullicient to overcome the resistance of the service meter to movement. The actuation of outsell relay 1 1 moves its contacts 9 and 13 to their almornuil positions and opens the circuit of line relay 12, allowing its contacts 15 and 16 to lreeome separated and caiising the line signal 17 to lzeconie cll'accd. The actuationof relay 44 closes its contacts 50 and 51, thus connecting the live pole of lottery A with the ring conductor 37 of the cord circuit through one of the coils of super- 115 visory relay 48 and also connecting the live pole of hattery A through the contacts 52 and 53 of relay 48 with the signal 54. The signal 54 is, however, not displayed for the reason that a path for current is now 00111 120 pleted from the live pole of lottery A. through contacts 56 and 51 of relay 44,0110 of the coils of relay 48, the ring conductor 37, the ring contacts 36 and 26 of the plug and {'ack, contacts 28 and 9 of the cutoff re- 125 lay, ine conductor 4, transmitter 6, receiver 7, contacts of the switch hook 8, line conductor 5, contacts 13 and 27 of the cut-oil relay 11, tip contacts 25 and 30 of the jack and plug, tip conductor 31, and the other coil of L30 relay 48 to ground. Current in this path the jack and plug and the contact 90 of the actuatcs relay 48 separating its contacts 52 and 53 and preventing the display of the signal 54. The operator now throws her listening key 80 and receives the number of the desired sulrscrihers station. She then raises her calling plug and touches the tip contact of that plu to the sleeve contact of the desired line. ii the desired line is bus the sleeve contact will be in connection Wit thesleeve contact of another, cord circuit anclwill therefore l e at a potential higher than that of earth. Current will therefore flow from the sleeve of the jack over the tip 35 of the calling plug, through the series contacts of the operators ringingkey, tip OOH. ductor 34, contacts 76 and 77 of the supervisory relay 47, conductor 78, auxiliary contacts 79 and 83 of the 0 erators listenin key 80. to earth through t e impedance coil 81. This current will sli htly alter the potential at the terminalo? the condenser 82 and will cause a partial dischargeof that condenser and wil turbance in the tertiary winding of the operators induction coil, this disturlance leing inductively reproduced in the secondary of the induction coil and in the operators receiver, indicating to the operator that the called line is l:usy.' If the called line is idle, however, no disturbance is heard by the operator and she therefore inserts her calling plug completely into the jack of the desired line causin its tip, ring and sleeve contacts 35, 40 am 45 to register with the tip, ring and sleeve contacts 25', 26 and 24 of the jack. Upon the insertion of the plug a circuit is completed from the livepole of hattery A through the coil of supervisory relay 47, conductor 46, sleeve contacts 45 and 24' of the plug and jack, conductor 23, coil of cut oli' relay 11 and the windings 19 and 20' of the line service meter 18 to ground. Current in this ath actuates rela s 47 and 11" but is not sul icient to actuate t c line service meter 18' The actuation of relay 11' connects the line conductors 4 and 5 with the ring and ti l) contacts of the jack, and the actuation of re ay 47 disconnects the operator's testing apparatus and completes the connection lictween the ortions 33 and 34 of the tip strand of t 1e cord circuit. It also completes the circuit of the supervisory signal 59 by closing the contacts 55 and 56, the signal 59 being now displayedto indicate to the operator that the subscribers are not et in conversation. The operator now t u-ows her ringin key 87 and impresses alternating current mm the ringing generator 89 through contact 88 of the ringing key, the tip contacts 35 and 25 of the plug and jack, contacts 27 and 13 of the cut-off relay 11, line conductor 5, condenser 2, annunciator 3, line conductor 4', contacts 9 and 28 of the cut-oil relay 11, ring contacts 26 and 40 of therefore cause a dis-.

ringing key 87 to ground. ing alternating passes through the condenser 2 and sounds the annunciator 3'.

When the called subscriber ansn'crs his call, the ringing key being now released, a path is completed from the live pole of battery A through contacts 55 and 56 of relay 47, one of the coils of relay 49, the ring condoctor 39 of the cord circuit, ring contacts 40 and 26 of the plug and jack, contacts 28 and 9' of the cut-off relay 11, line conductor 4, transmitter 6, receiver 7. the non closed contacts ofv the sr. itch hook 4. line conductor 5, contacts 13 and 27 of cut -oll rclay 11, tip contacts 25 and 35 of the jack and log, tip conductor 34, contacts 76 and 75 o sleeve relay 4:7, tip conductor 3-; and the other coil of supervisory relay ll! to ground. Current in this path actuatcs the relay e scparating its contacts 57 and 5s and eflacmg the supervisory signal 5!). 'Phis indicates to the operator that the called snbscriber has answered his call, and it is now the duty of the operator to register a call against the calling subscriber. 'lhc actuation of relay 49 connects battery through contacts 57 and 60 of that relay, conductor 61 and the coil of relay 62 to ground. This actuatcs the relay ('2 and completes a locking circuit through its own contacts ()3 and 64 and the conductor 65, this locking circuit being in parallel with the contacts 60 and 57 of relay 49. The actuation of relay 62 closes its contacts 66 and 67. The operator now depresses the service meter key 69 and completes a circuit from the direct current generator 72, which is of a voltage somewhat higher than that of the main battery A through the coil of the position meter 71, contacts 70 and 68 of the service meter key 69, contacts 67 and 66 of relay (i2, conductor 73, the low resistance coil 74 of relay 4-1, condoctor 42, sleeve contacts 41 and 24 of the plug and jack, conductor 23, the coil of cutoll relay l1 and the coils 19 and 20 of service meter 18 to ground. The current in this path actuatcs both the position meter 71 and the line service mctcr lS and docs not allcct the relay 44;, the winding 74 being connected in the direction to magnotizc tliv core of the relay with the same polarity as it was 1nagnctizcd by the current formerly passing through the coil 43 of that relay. It is true that there will be a-reversal ol' the current passing through the coil 43 but the current through the coil 74- will be of greater value and will overcome the dcmagnctizing cil'oct of the current through the coil 43. The ac tuation of the line service motor 18 n ill close its contacts 21 and 22 and place a shunt about the dill'ercntial coil 20. 'lhercforc, when the key 69 is released the dill'orcntial ell'ect of the coil 20 having been removed, the service meter 18 will remain in its actu This current hcated condition, the current from the battery A being sutlicient to maintain the actuation of this registering device.

When the subscribers 'have terminated their conversation and have replaced their receivers upon their respective switch hooks the circuits of relays 4H and 49 at the central oil cc are severed and the contacts 52 and 53, and 57 and S of those relays are again closed, com leting the circuits of the supervisory signa s 54 and 59, these signals being displayed to indicate to the operator that the conversation has terminated.

'lhe-object of making the relay 62 a lock ing relay is to give the operator suilicient time in uhich to actuate the service meter key (3!). This may be done even after the conversation has been terminated because the circuit of relay 62 is no longer controlled by contacts of relay 4),

When the operator receives the disconnect signs] by the display of the lamps 54 and 59 she removes her calling and answering plugs from their respective jacks and thereby scvers the circuits of relays 43 and 47. This allows the cut-oil' relays Hand 11 to r sume their normal positions and allows the s rvice meter 18 to fall back to its normal position. "The removal of the plugs also causes the opening of contacts 51 an of relay 43 and contacts 56 and of relay 47. This opens the circuits of the supervisory signals 54 and 59 and causes those signals to be ctt'accd. lhe apparatus is now in its normal condition and all of the signals are ell'accd.

W hilc I. have show n and described my invention with respect to certain details and combinations it 1s to be understood that I do not wish to be too strictly limited thereto, man deviations and modifications being posslble without in any way departing from the spirit or scope of my invention.

1 c aim:

1..In a telephone system, the combination with a telephone line, of a service meter for the line having differentially wound coils normally in series, contacts of said service meter adapted to shunt one of said coils when the meter is actuated, a cord circuit, a pair of sourccs associated with the cord circuit. one of said sources being connected with the service meter when the cord is connccted with said line, and being of insuflicient elect ro-motive force to actuate the service meter, and the other source being adapt ed to be tcmporarilyconnected with the service meter during the connection of the cord with the line, said source being of sufficient elm-tro-molivc force to actuate the service meter, substantially as described,

1;. In a telephone system, the combination with a telephone line, of a cut-ofl' relay tor the line, a service meter connected in series tl-n-rewith ainthaving a pair of series coils connected dill'ercntially, one of said coils having more turns than the other, whercb r the magnetizing force of the larger coil wil not be entirely overcome by the smaller coil, :1 pair of contacts associated with said service meter and adapted to shunt one ofssaid coils during the actuation of the meter, a cord circuit to connect with the line having a pair of sources associated therewith, one of said sources being of suilicient electro-motivc force to actuate the outwit relay but not the service meter, and the other being of sufficient electro-motive force to actuate both the service meter and the cut-off relay, the former source being suilicient to maintain the actuation of the cutoff relay and the service meter after the service meter has been once actuated, substantially as described.

3. In a telephone system, the combination with a telephone line, of a service meter for the line connected with one of the contacts of the line jack, a cord circuit to connect with the line, a pair of sources associated with the circuit, a relay for said cord circuit having two' coils, one of said coils being permanently connected between said contact of the cord, circuit and one of said sources, and the other coil of said relay being adapted to be temporarily connected between the contact of said cord circuit and the other of said sources, curruit through the two coils being adapted to magnetizc the relay to the sanic polarity, substantially as described.

4. In a telephone system, the combination with atclcphone line, of a cut-off relay, :1 service meter for the line having two coils connected in series, a cord circuit to connect with the line, a pair of sources associated with the cord circuit, a relay associated with the cord circuit having a coil connected in the circuit with one of said sources and said cutoii' rclay and service inctcr when the cord is connected with the line, current from said source being insutlicient for the actuation of the servlcc meter, 3 second coil of said relay being adapted to be connected in the circuit between said second source and the cut-oil relay and service meter, the second source being of higher potential than the first and being ol sulhclcnt eicctronnotive force to actuate the service meter, the current in the first coil of said relay being lOVOl-SCd in direction when the second source of current is connected, current through the second coil of said relay being suflicicnt to overcome the magnetic cil'cct ol' the current in the first coil ol' said relay, whereby the polarit of said relay will not be changed, substantially as describgd.

5. Iii a telephone system, the combination with a telephone line, of a cord circuit to connect therewith, a service meter for'the line and a supervisory relay for the cord cir' ouitrconnected in series when the cord is connected with the line, e pair of coils for said relny, one of said coils being permanently the other of said coils bcingznilepted to be temporarily connected in the circuit of the service meter during the connection of the cord with the line, current in said letter coil being suflicient for the actuation of the service meter and the current in the former coil being sullicient to maintain the actuation of the service meter thereafter, substantially as described.

6. In a telephone system, the (.uiiibinnlloll with a. telephone line, of a service meter and a cut-off relay connected in series, jocks for the line having a contact. connertl-d with the coils ol the cut-oft relay :1 {iii the service meter, at cord circuit'to connect with the line having at contact to register with the contact of the jack, :1. pair of sources associated with the cord circuit, a. supervisory rcluy having 0, coil connected bctwecn ne oi said sources and the contact of the cord circuit und having :1 second coil :uhrpted to be connected between the other of said sources and said contact of the cord circuit, the first source being of insufficient elcctro-motive force to actuate the service meter, and. the second source being of sull'icient electro -motive force to actuute the service meter, and the first source being of sullicientclcctro-motive force to maintain the actuation of the seryice meter after it had been actuated by current from the second source, substantially ELS described.

7.. In a telephone system, the combination with atelephone line, of at service meter and n cut-ol't' relay connected in series, jacks for the line having it contact connected with the coils of the cut-oil relay and the service metcr, a. cord circuit to connect with the line he. ring a contact to register with the contact of the jack, 2). pair of sources associated with the cord circuit, a supervisory relay having two coils, one of said coils being connected between one of said sources and the contact of the cord circuit, said source being adopted to furnish current sufiicient for the uctun ticn of the cut-oil relay but insullicient for the actuation of the service meter, the second coil of said supervisory relay being adapted to be connected between the contact of said cord circuit and said second source of cur rent, said second source being of at potcntiul snliicicnt for the actuation of the service. meter, the current from said second source through a coil of said supervist'n'y rchiy being sutlicicnt to maintain said relay magnetized with the some polarity us it was magnetized by the current through its first coil, whereby when the second source is disconnected the magnetism in the core of said supervisory relay wiil not be reversed and there will be no inductive current puss through the service meter therefrom which would demognetizc it and render it cnpnbie of a second registration, substantially as described.

8. In it telephone system, the combination with a telephone line, of a service meter for the line having differentially wound coils ol unequal numbers of turns, and means for shunting one of the coils of suid'service meter whereby the current in the other coilwill notunte the meter, substantially as described.

Signed by me at Chicago, county of (ook, and State of Illinois, in the presence of two witnesses.

WllildAM ltEll). Wit ncsses:

Crin roin) U. BRADBURY, MARJORIE E. (linen. 

